STX RC MC38 & MC38A difference?

[mattbrown]

Does any one know what the difference is between the two models of rear hub?

 

[KermitGKona88]

One 7 speed one 8 speed?

 

[mattbrown]

No, both are 8 speed. I have both but don't want to take the freehubs apart. Was just wondering if there was something obvious.